All categories

2 years ago

Solve the system of equations using substitution. y = 2x – 10 y = 4x – 8

Mathematics

2 answers:

Semmy [17]2 years ago

4 0

This equality are equal so2x-10=4x-8
-2=2x
X=-1

Dmitry_Shevchenko [17]2 years ago

3 0

If this paper dosent help u solve it on Your own i can walk u through it

You might be interested in

Please help I’ve been struggling for ages!

Lapatulllka [165]

Answer:

"D" only 1 & 2

Step-by-step explanation:

3 0

2 years ago

The profit (P) in dollars, for a company is modeled by the function P(x)=-750x^2+15,000x,where x is the number of items produced

OLEGan [10]

$-750x^2+15000x$

But x must be a natural number, so the answer is $x>20$ .

5 0

2 years ago

A survey was conducted to determine whether hours of sleep per night are independent of age. A sample of individuals was asked t

alekssr [168]

Answer:

Sleep hours per night is independent.

Step-by-step explanation:

Given the data:

Hours of Sleep 39 or younger 40 or older

> 6 _____38 36

6 to 6.9 _ 61 58

7 to 7.9 __76 74

8 or more 65 92

The Chisquare statistic is to be used to perform the analysis :

The hypothesis :

H0: Sleep hours per night is independent

H1: Sleep hours per night is not independent

χ² = (observed - Expected)² / Expected

To save computation time. We could use a Chisquare calculator to perform the analysis :

The test statistic = 4.0061

The degree of freedom = (row - 1) * (column - 1)

Degree of freedom = (4-1)*(2-1) = 3*1 = 3

The Pvalue = 0.261

Since, Pvalue > α ; We fail to reject the H0 ;and conclude that sleep hours per night is independent.

______________total ___%

> 6 _____38 36__ 74 __ 14.8

6 to 6.9 _ 61 58 __ 119 __23.8

7 to 7.9 __76 74___150__30

8 or more 65 92___157__31.4

_______240 _260__500_100

7 0

2 years ago

Does the graph below represent a proportional relationship?

aleksklad [387]

The answer is A.
The reason being straight lines mean equal proportions, while curved lines are exponential or quadratic.

6 0

2 years ago

Read 2 more answers

The number of hours worked per year per person in a state is normally distributed with a standard deviation of 39. A sample of 1

evablogger [386]

Answer:

The 98% confidence interval for the population mean number of hours worked per year per person is (2146, 2193).

Step-by-step explanation:

The question is incomplete.

The number of hours registered in the sample are:

2051 2061 2162 2167 2169 2171

2180 2183 2186 2195 2196 2198

2205 2210 2211

The sample mean can be calculated as:

$M=\dfrac{1}{n}\sum_{i=1}^n\,x_i\\\\\\M=\dfrac{1}{15}(2051+2061+2162+2167+2169+2171+2180+2183+2186+2195+2196+2198+2205+2210+2211)\\\\\\M=\dfrac{32545}{15}\\\\\\M=2169.67\\\\\\$

We have to calculate a 98% confidence interval for the mean.

The population standard deviation is know and is σ=39.

The sample mean is M=2169.67.

The sample size is N=15.

As σ is known, the standard error of the mean (σM) is calculated as:

$\sigma_M=\dfrac{\sigma}{\sqrt{N}}=\dfrac{39}{\sqrt{15}}=\dfrac{39}{3.873}=10.07$

The z-value for a 98% confidence interval is z=2.326.

The margin of error (MOE) can be calculated as:

$MOE=z\cdot \sigma_M=2.326 \cdot 10.07=23.43$

Then, the lower and upper bounds of the confidence interval are:

$LL=M-t \cdot s_M = 2169.67-23.43=2146\\\\UL=M+t \cdot s_M = 2169.67+23.43=2193$

The 98% confidence interval for the population mean is (2146, 2193).

3 0

3 years ago